The present invention relates generally to a process for producing a grooved foil material that is utilized in the production of a Metal Matrix Composite (MMC) sheet product. In one form, the process produces a MMC sheet product having a continuous spiral groove. More particularly, the present invention relates to a method of making a grooved foil sheet material that is utilized in fabricating an internally reinforced metal matrix composite ring. Although the present invention was developed for use in gas turbine engines, certain applications may be outside this field.
Many metal matrix composite structures have been designed to provide the required mechanical properties to operate in a hostile environment. Metal matrix composite structures can be fabricated by a number of techniques including foil-fiber-foil, coated fiber, ribbon wound fiber and wire-fiber. The matrix alloy chosen to form the MMC structure generally determines which of the above fabrication techniques is feasible. For example, a Ti-6-4 MMC structure can wire-fiber. The matrix alloy chosen to form the MMC structure generally determines which of the above fabrication techniques is feasible. For example, a Ti-6-4 MMC structure can generally be fabricated by using any of the above described techniques since the material Ti-6-4 is available in foil, powder, ribbon, and wire form. In contrast, certain high temperature titanium alloys such as Ti-22Al-26Nb (orthorhombic titanium) are only available in a sheet or powder form. Therefore high temperature titanium and titanium-aluminide alloy MMC structures are generally fabricated by the foil-fiber-foil method.
When fabricating MMC structures with the foil-fiber-foil technique, it is often desirable to utilize grooved foil. A continuous high strength monofilament is laid in the grooved foil and multiple loaded foils are stacked and consolidated to form the structure. The grooving provides a uniform fiber to fiber spacing in the consolidated structure. It is known that grooved foil has successfully been used in producing MMC structures formed of a conventional titanium matrix. One prior technique of producing grooved foil of a conventional titanium material has employed a photolithographic etching technique. However, these photolithographic techniques have proven unsuccessful in producing well-defined grooves in high temperature titanium aluminide alloys such as Ti-22Al-26Nb.
The present invention allows for the production of a grooved foil sheet product in a novel and nonobvious way.